Analogues of polydeoxyribonucleotides having 3'-5'-phosphoramidate linkages, called poly-5'-azanucleotides, are being synthesized by new methods that are simple and efficient. Defined oligomer sequences of 8-10 units containing the four common nucleobases will be examined as substrates or templates for polymerases and ligases to prepare the complementary DNA and RNA sequences. The poly-5'-azanucleotides will be studied also as primers for DNA sequencing. BIBLIOGRAPHIC REFERENCES: Gibbs, D.E. Synthesis of Phosphoramidates with Silylphosphites and Azides. Tetrahedron Letters, in press (1977).